Installing a Kitchen Sink Strainer

Stainers are the unsung heroes of the kitchen, yet they are almost always the first component to show their age. Over time, the seal between the metal flange and the sink basin breaks down, leading to that slow, persistent drip into the cabinet below. Replacing one is a straightforward task that eliminates a major source of water damage in your vanity or kitchen cupboard. Successfully installing a new strainer requires a clean work surface and a steady hand when applying the sealant. When done well, the strainer sits perfectly flush with the sink floor, creating a watertight bond that stands up to years of daily use. You are not just stopping a leak; you are refreshing the most high-traffic drain point in your home.

1. Stop the water first. Disconnect the P-trap and tailpiece from the bottom of the existing sink strainer using channel-lock pliers. Place a bucket underneath to catch any residual water trapped in the pipes.
2. Extract the old strainer. Loosen the large locking nut on the underside of the sink. Once removed, push the strainer body up through the sink opening and lift it out.
3. Start with bare metal. Scrape away all old putty or silicone residue from the sink hole with a plastic scraper. Wipe the area clean with denatured alcohol to ensure the new seal adheres perfectly.
4. Seal with fresh putty. Roll a golf-ball-sized amount of plumber's putty into a long, thin rope and wrap it evenly around the underside of the new strainer flange. This creates the gasket that prevents leaks.
5. Lock it down tight. Insert the strainer into the sink hole and press down firmly. From underneath, slide the rubber gasket and friction washer onto the strainer threads, then screw on the locking nut by hand.
6. Finish without overtightening. Use a strainer wrench or large pliers to tighten the locking nut until the excess putty squeezes out from under the flange inside the sink. Wipe away the excess putty with a damp cloth.